Chuck



April 13, 1954 H. E. BALSIGER CHUCK 2 Sheets-Sheet 2 Filed March l5,195C INVENTOR SIGER /ARULD E. BAL

BY /Qkw TTURNEY Patented Apr. 13, r1954 2,675,240 oHUoK Harold E.Balsiger, Waynesboro, Pa., assigner to Landis Tool Company, Waynesboro,Pa.

Application March 15, 1950, Serial No. 149,857`

2 Claims. l

This invention relates to chucks, particularly chucks of the type forengaging internal and external surfaces `of work pieces.

Most chucks used for this purpose consist of angularly spaced grippingmembers which often distort or deform the work piece to such an extentthat it is difficult or impossible to machine or grind the externalsurface thereof.

It is, therefore, an object of this invention to provide a chuck havinga gripping device which engages the work piece in a continuous contactover the entire periphery thereof.

A further object is to provide a chuck which will not only grip the workpiece without distortion, but will also serve to shift the Work pieceaxially against a locating surface.

ln the drawings, Y i

Figure l is a plan view of aheadstock spindl mounting.

Figure 2 is an enlarged view of the chuck.

Figure 3 shows my invention adapted for grip ping the external surfaceof a work piece.

Figure 4 discloses an alternate arrangement for gripping an externalsurface.

The spindle I is rotatably mounted in bearings and |2 and housing I3.Said spindle is rotated through a pulley driven from any suitable sourcethrough belts 2|. A draw rod 25 passes axially through said spindle,being supported at one end in a block 26. A sleeve 2l threaded to areduced portion in said block is slidably mounted on an end portion 28of spindle I0. Said sleeve has a flange portion 29, in which has beencut a notch 30. A pin 3| in pulley 20 has a protruding portion whichengages said notch so that said sleeve block and draw rod are rotatedalong with the spindle.

Said draw rod is held in left-hand or closed position by means of aspring which bears at one end against a shoulder 35 inside said Spindleand at the other end against a, collar 3l adjustably mounted on said rod25. The means for shifting said rod against said spring consists of anarm pivotally mounted at the lower end on one end of a rod 4I. At theother end of said arm is a yoke portion, the two arms 42 and 43 of whichengage or contact with an eccentric 4f! on shaft 45, which is suitablymounted in housing' |3. Said shaft may be oscillated by means of a lever50. When so oscillated, a roller 5| mounted at an intermediate point onarm 40 engages a grooved ring 52, which in turn engages the flangeportion 2B of sleeve 21. v

The chuck consists of a conical arbor 60 having a flange portion 6|which is attached to a similar means of a, ring |01.

flange E2 on the end of spindle I0. The smaller end of said cone-shapedmember has been machined to form. a cylindrical portion t5 and ashoulder 56. The outer end of said cylindrical portion is chamfered atlil inany suitable manner, not necessarily that shown in the drawing.

Draw rod 25 is slidably supported in the small end of said arbor 60. Aheaded member I0 is removably mounted in the end of draw rod 25. Thediameter of said headed member 'lil is slightly less than that of workpiece ll. A resilient ringlike member l2 is mounted on the smallerdiameter 3 of said headed member between the head thereof and the end ofcylindrical portion 65.

When draw rod 25 is shifted to the right by lever 5o against the actionof spring 35, the `ring l2 barely touches the inside surface of Workpiece ll. However, when lever is released, spring 35, acting againstcollar El, shifts draw rod 25 and headed member 'l0 to the left.

A resilient ring 'l2 is compressed between the headed portion 'l0 andthe cylindrical portion E5. When so compressed, it ows in the directionof least resistance, first, radially against the inside surface of thework piece 'Il and 'then axially into the space between the surface ofthe chamfered portion and the inside surface of the Work piece. Thisaxial movement serves to move the work piece slightly in the samedirection, locating it against the shoulder 65.

Figure 3 shows a chuck for gripping the external surface of a workpiece. A chuck body |00 is attached to flange 02 on spindle Ill by meansof screws |0l. Said chuck body is cylindrical in i shape and has a bore|02 into which the draw rod 25 extends. The outer end of said chuck bodyhas a counterbore |03 of a diameter to accommodate the work piece |0.The shoulder H34 formed by said counterbore serves as a means foraxially locating said work piece. At the outer edges of said counterboreis a chamfered surface |05.

A resilient ringlike member |00 of substantially the same diameter asthe outside diameter of the work piece is held against said chuck bodyby Said ring in turn is held in place and actuated by studs |08extending through holes |09 in said chuck body 00. The inner end of saidstuds |08 is attached to a member I i, which in turn is attached to drawrod 25. Said chuck body |00 has radial slots ||2 and ||3 foraccommodating said member When pressure is exerted on resilient member|00 by movement of ring |01 toward the chuck body, said resilient memberdeforme both radially to grip the work piece and axially into the spacebetween said chamfered surface and the surface of said work piece tourge said Work piece against the locating shoulder |04.

An alternate form of my invention for grip'- ping external surfaces isshown in Figure 4. The chuck body |20 attached to flange 62 has a bore|2| for receiving work pieces I0. AThe bottom of said bore is relievedto provide a locating shoulder |22.

An annular groove |23 in said bore provides a close fit for resilientmember |24. The inner edge of said groove has a chamfered surface |25.

Air or other fluid under pressure from any suitable source is Idirectedthrough a passage |20 in chuck body |20 to groove |23. When pressure isapplied on member |24, said member is deformed radially to grip the workpiece, and axially into the space between said chamfered surface andsaid work piece to urge said Work piece into engagement with shoulder|22.

1 claim:

1. 1n a headstock having a rotatable spindle, a chuck comprising amember mounted on said spindle and having ymeans for locating a workpiece axially thereon, means for gripping a work piece including achamfered cylindrical member, a solid ring-like member of materialhaving a high degree of elasticity and subject to substantial change incross section in response to the application of pressure, said ring-likemember being mounted adjacent the chamfered por tion of said cylindricalmember, said chamfered portion providing an annular recess between saidcylindrical member and said work piece, means for applying pressure onsaid ring-like member against the chamfered end of said cylindricalmember, said pressure means and said recess providing a conned space towhich said ring-like member conforms in cross section in response tosaid pressure means, said change in cross section L 2. In a headstockhaving a rotatable spindle, a chuck comprising a member mounted on saidspindle and having means for gripping a work piece including acylindrical arbor portion having a shoulder at the inner end thereof forreceiving a ring-like or tubular Work piece, a drawrod extending throughsaid spindle and arbor having a headed portion thereon, a chamferedportion on said-arbor .adjacent the headed portion of said draw-rod andforming a conned space between said headed portion and said Work piece,a resilient ring-like member on said draw- Y rod between said arbor andsaid headed portion,

said resilientl member being formed of a material having a high. degreeof elasticity and being capable of .substantial change in cross sectionunder pressure, means for shifting said draw-rod axially, said resilientmember being responsive to pressure exerted by said headed member toflow radially into engagement with the surface of the said work pieceand axially into the remainder of said conned space, whereby to urgesaid Work piece against said shoulder.

References Cited in the le 0f this patent UNITED STATES PATENTS 'mil

